In recognition of the significant expenses associated with hydrocarbon wells, added emphasis has been placed on well logging, profiling and monitoring of conditions throughout the life of a well. As a result, the detecting and monitoring of well conditions over the years has become a more sophisticated and critical part of managing well operations.
Initial gathering of information relative to well and surrounding formation conditions may be obtained by way of a logging application. That is, equipment at the surface of an oilfield adjacent to the well may be used to deploy a logging tool in the well. Often, an electrically conductive logging cable is used to deliver the logging tool into the well. The logging cable may include a variety of power and communicative lines incorporated into the cable along with a host of isolating and protective polymer layers. As a result, the cable may be of relatively substantial weight, strength, and profile. Thus, the cable may be well suited for delivery of the logging tool to significant well depths without undue concern over the accommodated load of the tool or perhaps the increasing load of the cable itself.
While well suited to accommodate a significant amount of load, the use of such cables as described above means that the equipment positioned at the surface of the oilfield may be fairly substantial in terms of footprint and power requirements therefor. Similarly, the set up and performance cost of running the operation may also be quite significant.
Due to the costs involved, a cabled logging application as described above is often bypassed in favor of a more cost effective “slickline” logging application. That is, rather than employing an electrically powered and/or electrically communicative cable as in the case of a cabled application, a comparatively lower profile line without such capacity may be employed in a conventional slickline application. The slickline is a relatively unitary line used to deliver the logging tool which includes no electrically conductive wiring. Thus, a downhole battery is provided and data obtained from the logging application may be processed after retrieval of the logging tool. Notably, however, due to the substantially lower profile and comparatively lower weight of the slickline, considerable expense may be saved. For example, expenses may be affected in terms of reduced surface equipment requirements, as well as reductions in expenses associated with set up, powering, and footprint requirements.
Unfortunately, while slickline reduces operational expenses, the lack of communicative capacity eliminates the possibility of acquiring any real-time logging information. As noted above, logging data acquired via conventional slickline applications is processed only after the logging tool is brought out from the well. Depending on the depth of the well, this manner of logging retrieval and processing is likely to take up several hours of operational time at a minimum. Once more, there is no manner by which to communicate any malfunction of the logging tool or downhole battery during the operation. Thus, in cases where malfunction does occur, the entire operation may need to be re-run. Additionally, without the availability of real-time information, the possibility of any real-time downhole intervention in conjunction with a slickline logging operation is rendered useless or impractical.
Ultimately, in spite of the additional expense involved, logging applications are often run on wireline due to the unavailability of real-time downhole communication where slickline is employed. Indeed, even in circumstances such as shallow wells where the added load carrying capacity of wireline is of no particular benefit, the substantially more expensive wireline operation is often employed nonetheless due to the downhole communicative capacity provided.